Separable attachment-plug.



R. B. BENJAMIN.

SEPARABLB ATTACHMENT PLUG.

APPLICATION FILED DEO.4, 1909. wmm, Patented July 14,191

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SEPARABLE ATTACHMENT PLUG. APPLIUATION FILED DEC. 4, 1909.

1,1 03,251 a Patented July 14, 1914.

2 SHEETSSHEET 2.

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REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SEPABABLE ATTACHMENT-PLUG.

Specification of Letters Patent.

Application filed December 4:, 1909. Serial 1'0. 531,432.

Patented JuIy 14, 1914.

a and State of Illinois, have invented new.

and useful Improvements in Se arable Attachment-Plugs, of which the ollowing is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specificatlon.

This invention relates to improvements in attachment plugs of that class in which the part which makes connection directlywith a stationary socket may be separated, when desired, from the part which carries the binding terminals to which are securedthe leading-out conductors. 4

The rincipalbject of the invention is to provide an attachment plug-of the above class which is so constructed that when it is desired to manually separate the two parts thereof this may be done without jarring the fixture which carries the socket with which connection is made. To this end the device is so constructed that by givpart which is grasped by the hand, this being the part which'carries the binding screws and wires,,' the parts will readily separate.

Heretofore, as separable attachment plugs: have usually been constructed, the separation of the parts could only be efiected by withdrawing one of the parts from the other with a straight pull. This" has proved to be objectionable in many, instances, as where the socket with which connection is? made forms part of a chandeliercarrying a num- J When 5 her of lam s and shades. therefor; a direct pull is exerted to separate the parts the separation is resisted for-a time until the force exerted becomes atenough toovercome the resistanceof e clips or other parts which tend' to hold the members of the plug together, whereupon those mem-' bers separate with a sudden jerk which is liable to cause damage to" the chandelier, shades and the like. By'the use of my invention this difiieultyis overcome, it being possible to separate one part of the plug from the other without any undue force;

being employed or vibration caused. Sockets as heretofore constructed have also been defective in that, "to connect the parts to gether, it has usuallybeen necessary to force ahead or other enlarged portion, with a or't e like. -The jarring eifect resulting from this was objectionable for reasons stated above.

vention to provide a plug 0 the class described in which the two partsmay be connected together without any jarring effect. H In the accomplishment of the above objects I provide a cap member which is arranged to be screwed into the stationary contact and an end contact arranged for engagement with the corresponding contacts of the socket.

I then provide 9; lug member from which extend the lea 'ng-out wires, said mal strain exerted in a direction which would tend to cause the plug member to pull out of thecap' member will not be rewould ordinarily be placed uponthe device twill be finsufiicren't' to cause the parts to iseparate.

I also provide means for preventing any -jarring' efiect when the plug member and ioap member-are connected. The interlockfi'ng' parts upon the two separable members fare arrangedfto make connection when .one ;of said members is thrust directly into the :other. After the" arts have thus become locked together su cient resistance to the separation of said parts is offered to prevent the same from separating under ordinary jconditlons', as above stated, but if a slight Erotation isv given to the plug member relatively to the ca member, said parts auto- :matieally unl'oc the plug member being towed out of the cap member to some extent', thus insuring the parts remaining detachedfrom each other.

'- In the accompanying drawipgs, Figure 1 It is therefore a further ob'ec't of this insisted' to suchan extent as to prevent such separation, although any such strain as Y snapping action, between a pair of,'springs socket, which cap member carries a side I is a side elevational view of the device the two separable members put together;

' Fig. 2 is a bottom plan view of the upper closes the lower part of the same being removed; Fig. 5 1s a longitudinal sectional view of the device with the separable members connected with each other; Fig. 6 shows the device with the members separated, the cap member being shown in section on the line 6-6 of Fig. 2, while the plug member is shown in elevation; Figs. 7 and 8 are sectional views of the upper portion of the plug member, the sectlons bei'ng'taken on the lines 7-7 and 88 respectively of Figs. 3 and 4; Fig. 9 is a sectional detail view of the contact head of the plug, the section being taken on the line 99 of Fig. 6, looking in the direction of the arrows; Fig. 10 is a view showing fragments of the cap member and plug member of a modified form of my device; Fig. 11 is a fragmens tary view showing the cap member and plug member of this modified form in plan; and Fig. 12 is a detail section taken on the line 12 -12 (it-Fi 10, of the arrows.

Referring now to the drawings, the cap member comprises an insulating base 10 which occupies the upper portion and extends beyond .the upper end of a threaded metallic ring 11, which forms the outer side contact of the cap. Below the threaded portion of the ring 11 the latter is slightly contra'cted at 12, whereby a shoulder is formed upon which the base 10 rests, the base 10 being further secured in place by means of indented bosses 12 formed 11 on the rin near the shoulder created by t e contracte portion 12. In order that the base may be retained against outwa'rd movement in the ring, it. is formed with a pair of o positely.

disposed cavities 13, the material 0 the ring at its upper edge being bent over mto these recesses at 14. Surroundin the lower portion of the ring is an insu ating sleeve 15, the latter being prevented from slipping off the lower end of the threaded ring by forming the latter with a bead 16 at its lower edge and forming the insulating 'sleeve' with a'corresponding bead 17 which is occupied by the bead 16 of the ring.

The lower portion of the insulating base is chambered out at 18. From this'chamher a, passage extends upward throu h the base and opens'at the outer end of t 1e lat ter. A contact member comprisinga strip looking in the direction means of a hollow rivet 21 which extends through the a rture of the 'base and is headed over at its upper end to form a center outer contact for the cap member. When the cap member is screwed into a socket, electrical connection is made by the threaded ring 11 with the threaded contact of the socket and by the contact member 21 with the center contact of the socket. The lower ends of the legs 20 are bent inwardly and :then outwardl to form angular shoulders 22 for engaging and retaining a contact head with which the plug member is provided. The legs 20 are bent outwardly at 122, somewhat above the shoulders 22, to form an enlarged space between "the legs for a urpose which will be described below.

Sli ably mounted in the hollow rivet 21 is a plunger 23 having at its lower end a head 24, of somewhat greater diameter than ,the contact head of the plug member, which }is forced toward the pro ect-ions 22 by a spring 25 inserted between it and the lower end of the rivet 21. \Vhen the plu member is separated from the cap mem )er the head 21 will be ushed by the spring 25 against the shoulers 22 (Fig. 6) and will hold them separated ready for the reinsertion of the'conta ct head, but when the plug member is inserted into the cap member-the head 24 willtbe forced inward against the action of the spring 25 until itreaches the enlarged portion 22* when the shoulders 22 are permitted to sprm toward one another and grasp the contact ead.

" The lower or-plug member comprises an insulating base 26 made somewhat coneshaped and havin a metallic ring 27 ex-' ten ing above its ower and larger portion, this ring'bein turned over inward upon a shoulder 28 with which the base is formed.

The lower endof the ring 27 is drawn in outer screw threads thereon. cap 30 ininner and closes the threaded neck 29 and'is formed of insulating material and has a neck portion 31 which is threaded or screwed up within the neck 291 Between the upper edge of-the cap 30 and the shoulder caused by the drawing in of the material of the ring 27 is arranged an insulating ring 32 which extends laterally beyond the edge of the'cap so as to' be'capable of being readily grasped by the fingers of the person usmg the plug. Uponthe lower end of the base there is formed-a rojecting hump33 which extends downwar for a short distance into the neck 31 of the insulating'cap. Vhen the leading-out conductors are in position and the ca 30 is screwed up in place, the leading" out conductors are gripped between the in- 'ner"edge. of the upper end of the neck 31 ed of undue strain upon them, which strain would otherwise tend to tear the conductors from the binding terminals.

When the base 26 and the ring 27 carried thereby, which form the insertibl part. of the pl member, are thrust into the lower end '0 the cap member, electrical connection is made between the interior of the portion 12 of the ring 11 and the exterior of the'rin 27. To insure good electrical contact being made, .the portion 12 of the ring 11 is formed with a number of inwardly progecting humps 34 which make rubbing contact with the ring 27. A binding screw 35 is provided for making electrical con nection between one of the leading-out conductors and the ring 27, this bindin screw being carried by a tongue 36 formed y cutting the ring 27 vertically at each side of the screw 35, the tongue being setback into 'asuitable recess formed in the base 26. The binding screw 35 is provided with a nut 37 located in the recess in the base, this nut being prevented from rotating by the shape of the recess A passage 38 extends from the under side of the base u to the tongue 37, this passage bein provi ed for the accommodation of the eading-out wire which will extend therethrough and emerge at the left hand edge of the tongue 36 in position for attachment to the binding screw A chamber 39 extends down into the base 26 from the upper end of 'the latter. From The upper portion of the chamber 39 is enlarged imd1ameter to receive a contact piece 41, the lower, portion of which is cup-shaped. The contact piece 41 is held in position by a plate 42 which is provided with a pair of prongs 43, the latter being bent downward at a right angle with the body of the plate and extending through openings or passages,

which lead down from the chamber 39. The lower ends of the .prongs 43 are turned outward and extend laterally into suitable channels formed in the under side of the base 26. 'A binding screw 44 screws into the plate 42 and has its head sunk in the contact piece 41. An' opening 45 is formed in the contact piece 41 for the passage of the second leading-out conductor to the binding screw 44 after this conductor has been brought up through'the passage 40 and chamber 39. Y

The contact piece 41 is so shaped above the end of the base 26 as to form an oval stem 46, the greatest diameter of which is somewhat greater than the normal distance apart of the shoulders 22 of the spring legs 20 uponthe cap member. Above the stem 46,

stem 46.. The result of this is that the ex terior of the stem and the edge of the head 47, coincide at twodiametrically opposite points, while at two other diametrically op- I posed points the head projects laterally considerably beyond the stem 46, thereby forming a pair of shoulders 48 which are adapted to engage beneath the shoulders 22 of the spring legs 20 upon the cap member when tie plug member and the cap member are connected.

' When the plug member is to be connected to the cap member, it is merely necessary to push it forward into the cap member, when the head 47 will enter between the legs 20 which, it will be remembered, are held apart by the head 24 of the plunger (Fig. 6). As the head-47 enters between the legs 20 the plunger head 24 is pushed backward until it reaches the enlarged portion 22 between the legs. There is then nothing to prevent the legs from springing together and they do this, the shoulders 22 engaging under the shoulders 48 of the head 47 (Fig. 5). When it is desired to disconnect the parts of the device, the plug member is twisted through about 90 degrees. The .efiect of this is that the legs 20 are forced apart by the cam action of the oval stem 46 upon the shoulders 22. There is then no hold for the shoulders 22 upon the head '47, consequently the plug member is forced outward by the action of the spring 25 and head 24, the latter following the head 47 downward and again taking up the position shown in Fig. 6.

In the. modified form of my invention 1 with the oval stem'described above, the stem 50 and the jaws 49 bein of-corresponding shape. The head 51 of t e contact piece is of a diameter equal to the diagonallength' .'of the stem 50,50 that the corners of the stem will coincide with the edge of the head. This construction operates in precisely the same way as the form described above with the exception that the plug member. need" be turned to a less extent to eii'ect a separation of the members.

By the arrangement ot a head upon the the contact piece of the pill member, means are provided whereby a sllght-rotation (at most a movement equal to one-fourth of a complete revolution) of one art within the other unlocks the device. ery little effort is required in revolvin the plug member to separate the members, thus but little twisting efi'ect is imparted to the upper portion of the device. When the parts are brought to the proper angular relation to each other the lug portion is automatically thrust out by t e action of the head 24, thus not only is no direct ull upon'the plug required when the device is to be manually separated, but it is rendered'impos'sible to give such a pull to the device if the lugis turned to the unlocking position. t will thus be seen that in unlocking one part from the other the action is exceedingly smooth, there being complete freedom from the sudden breaklng away of one part from the other, with the consequent tendency to a reaction, which is common to other separable attachment plugs, and which reaction results in damage to fixtures, shades and the like. The plug also has the advantage that the connecting together of the parts is ef-- footed without any snapping or jarringac- While I have shown and described the separable members as consisting of a cap and a plug insertible into the cap it is to be understood that I do not intend to limit myself to this precise construction, or in any other way to limit the $00 e' of my inventlon except as pointed out 1n the appended clalms.

Having thus described my inventiomwhat I claim as new and desire to secure by Lettors Patent, is:

1. In a separable attachment plug, a pair of body members, one of which is adapted to be inserted into a socket, gripping means carried by one of said members, and a contacthead carried by theother of-said members and arranged to be gras ed.by said grlppmg means when said mem ers-are put together, said contacthead being provided w th a cam projection arranged to release said grip ing means when said members are rotate relatively to each other.

2. In a separable attachment plug, a pair of body members, one of which is adapted to be inserted into a socket, spri'n contact.

fingers carried by one of said mem rs, and a contact head carried by the-other of said members and arranged to be inserted between said spring contact fingers and 'grasped thereby when said members are force said contact put together, saidcontact 'headbeing rovlded with-a cam fiprojection arrange to ngers apart when. the

members are rotated relativelyto each other. 3. A separable attachment plug com rising two separable members, one of w lab is adapted for insertion into a wall. socket and the other "of" which carries bindingmeans for releasin v ,means for forcing said members apart when terminals for receiving leading in wires,

interlocking contacts carried by said members, said contacts bein arranged to lock together when the mem ers are connected, said contacts, and

said contacts have been released.

4. A separable attachment plug comprising two separable members, one of which is adapted 'for insertion into a wall socket and the other of which carries binding terminals for receiving leading in wires,

interlocking contacts carried by said members, said contacts being arranged to lock together when the. members are connected, means whereby said contacts are released upon one of said members being rotated with respect to the other, and means for forcing said members a art when said contactshave been release 5. Ina se arable attachment plug, a member adapte to be inserted into a socket, a second member adapted to be connected with said first member, gripping means on one of said members, cont-act head carried.

by the other member and arranged to be grasped by the gripping means when said mem ers are connected with each other, said contact head' being provided with a cam projection arranged to release said grip mg means when the members are rotate and auxiliary means tending to force said members apart.

6. In a separable attachment plug, a pair of members, one of which is adapted to be inserted into a socket, spring contact fingers carried by one of said members, a contact head carried by the other member and arranged to enter between said contact fingers when said members-are connected to each other, and auxiliary means tending to force said members apart.

7. In an attachment plug, an outer mem, ber provided with an outer contact adapted for engagement with the corresponding contact of a wall socket, an inner member insertible into said outer member and pro-- vided with means for receiving leading-in wires, means tending to separate said members, means normally locking said members together, and means arranged to unlock said locking means upon one of said members 'beingrot-ated with respect to the other.

8. In an attachment plug, an outer member provided with an outer contact adapted for engagement with the corresponding contact of a wall socket, an inner member insertible into -'said outer. member and provided with means for receiving'leading-in wires, spring pressed means tending to separate said members, means for normally lockin said members together, and means for un ocking said lockin means upon one mimber being rotated with respect. to the ot er. p

9. A separable attachment plug comprismg a member, a contact head carried there by, a second member for connection with said first member, a spring contact device carried thereby and adapted to engage under said head when the members are connected together, and means for holding said contact device out of the path of said head during the first part of the connecting movement and allowing said contact device to move into engagement with said head after the connecting movement has been com pleted.- v

10. A separable attachment plug comprising a member, spring contact fingers carried thereby having retaining shoulders thereon, said contact fingers being formed to create an enlarged space between them above said shoulders, a plunger arranged to enter between said fingers and retain them in a separated position, a second member, and a head carried thereby arranged to enter between said contact fingers and force said plunger upward into said enlarged space whereby said contact fingers are enabled to close upon said head-and retain it in position. I

11. In an attachment plug, a pair of separable members, means tending to separate said members, a locking device for normally holding said members together so as to be capable of separation upon a pull being exercised upon one of them, and means for releasing said locking device upon one of said members being rotated with respect to the other member.

12. In an attachment plug, two separable members, one carrying contacts for engagement with the cont-acts of a wall socket and the other carrying binding terminals, means tending to separate said members, a locking device for normally holding said members together so as to be capablefof separation upon a pull being exercised upon one of them, and manually operable means for releasing said members.

In witnes whereof, I have hereunto subscribed my name in the presence of two witnesses.

REUBEN B. BENJAMIN.

Witnesses:

CHARLES G. Corn, (3n L. Hornms. 

